Add a class Borrower that extends User. The constructor of the Borrower class takes a name and a number of books borrowed by the borrower. If the number of books given as argument is strictly less than zero, then the constructor must throw a NotALenderException with the message "A new borrower cannot lend books.". The borrower class does not have any instance variable.java代码

Sure, here's your Java code:

public class Borrower extends User {
    public Borrower(String name, int numBooksBorrowed) throws NotALenderException {
        super(name);
        if(numBooksBorrowed < 0) {
            throw new NotALenderException("A new borrower cannot lend books.");
        }
    }
}

Here, we have defined a `Borrower` class that extends the `User` class. The constructor of the `Borrower` class takes a name and a number of books borrowed by the borrower. If the number of books given as argument is strictly less than zero, then the constructor throws a `NotALenderException` with the message "A new borrower cannot lend books.".

Note that we are calling the constructor of the parent `User` class using the `super` keyword, passing in the `name` argument. The `Borrower` class does not have any instance variables.